1. Field of the Invention
This invention primarily relates to the caster structure of a treadmill runner concerning its pushing motion. As for a better description, this newly invented structure can let runner's frame be pushed to slide directly after pack its running board and framework to their upright folding position.
2. Description of the Prior Art
The said treadmill runner is a track-type sport facility used for indoor exercise. Its typical assembly is to have one floor-type front prop and one floor type rear prop installed at front and rear end base of the treadmill runner's framework respectively. They can set the running board to demonstrate a slightly tilt status and stick to ground (standby position for immediate use) when the placement of framework is done. At this moment, user can run on the running track to do the running exercise. When storage or transportation of this treadmill runner by folding it is desired, user can flip the runner board into an upright folding position and lessen its space occupation largely.
Thus, take the precedent of consuetudiary patent U.S. Pat. No. 5,676,624 for example, (as shown on FIG. 1), after running board 12 is lifted in a vertical status, its floor-type front prop 14 will become the supporting point and will bear the total weight of runner frame 10. Afterward, there are caster assemblies 16 equipped to one suitable side of floor-type prop 14 and installed at its both ends individually. Therefore, when pushing runner frame 10 to move is desired, this can be done by just simply slanting runner frame 10 in an adequate angle and letting caster assemblies touch floor 18 to perform their works (as shown by dash line on the figure), and then smoothly pushing runner frame 10 to move.
Although the structural design of caster assemblies 16 described in the precedent of consuetudiary patent did accomplish the expected effect, however, we still can have further findings if we conduct a closer observation. Because of the integrated weight that runner frame 10 is bearing is not a light weight, also, when it is tilted to its push-to-move position, the floor-type prop 14 has completely separated from floor 18 and leaves the caster assemblies 16 as the only one supporting point. Under this circumstance, runner frame 10 may fall down to bump into the ground 18 due to user's careless incident or obstacles on the ground while user is pushing to move runner frame 10 without paying special attention to the surrounding environment. As a result, this may seriously damage the runner frame 10 and hurt the user when runner frame 10 is falling.